I'm not a lawyer but it's my understanding you never lose constructive possession if you are present with the firearm. For instance, you can take a firearm to

I'm not a lawyer but it's my understanding you never lose constructive possession if you are present with the firearm. For instance, you can take a firearm to an engraver to have it engraved while you wait, so long as you are present for the engraving operation it isn't considered a transfer. I'm unsure if 922 (a) (5) even applies in that case, but IANAL. I would be quite shocked if anyone was prosecuted under 18 U.S. Code § 922 (a) (5) for a firearm loaned exclusively for sporting purposes, but this is not legal advice. Personally I can think of at least one long-running skeet/trap range that will lend out shotguns for sporting purposes without any representative being anywhere near present while you use it, and they've been on the radar in plain sight doing this for decades across thousands of people (and they'll lend to any tom/dick/harry without any scrutiny).